Pentair · Under-Sink RO Systems
Pentair FreshPoint GRO-350B 3-Stage Reverse Osmosis System - Standard System
Lower-concern pick for RO systems; standard materials, but Pentair discloses nothing on PFAS.
The FreshPoint GRO-350B uses conventional RO membrane and carbon filtration technology without known PFAS-prone coatings. Pentair makes no public PFAS disclosures for this model. While reverse-osmosis and activated-carbon filters are generally lower-risk, lack of transparency and absence of third-party verification leave some uncertainty.
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RO membrane, carbon pre-filters, stainless steel housing
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
No PFAS disclosure
No public statement about PFAS in this product.
Uncoated safe material
Bare, uncoated material (cast iron, stainless, carbon steel, or glass) with no surface treatment to contain PFAS.
The full breakdown
What it's made of and why it matters
The GRO-350B uses a multi-stage design: sediment pre-filter, granulated activated carbon cartridge, and a reverse osmosis membrane, all housed in stainless steel. The carbon and membrane are the active filtration elements and are not known to leach contaminants into water under normal use. Stainless steel housing avoids corrosion and metal leaching that can occur with lower-grade metals in other systems.
The brand's record and disclosure
Pentair is a large water treatment manufacturer with NSF/ANSI certifications for many products, though specific certifications for the GRO-350B should be verified on the product sheet. The company does not publicly disclose PFAS reduction testing or manufacturing practices for residential RO systems. No major safety recalls or contamination incidents are on record for this model.
How it compares in its category
Three-stage RO systems are mainstream and generally considered the baseline in residential reverse osmosis. This unit sits in the mid-range for under-sink installations; some competitors claim additional polishing stages or certified contaminant reduction lists. Stainless housing is a standard safety feature in this category, avoiding cheaper plastic housings that can off-gas or degrade.
If you buy it
Replace pre-filter cartridges every 6-12 months and the RO membrane every 2-3 years to maintain performance and prevent bacterial growth in the unit. Do not store the system in freezing conditions, as ice can crack the membrane. Flush the system monthly if unused for extended periods. Follow the manufacturer's maintenance schedule closely; neglect is the primary risk factor for this category.
Beyond PFAS: other things we checked
Established hazard classes for this product type, assessed from public information. These never change the PFAS grade; a Likely flag caps the Verdict at “Buy with care.”
Bacterial growth in storage tank or housing
RO systems hold treated water in a storage tank; if not maintained or flushed regularly, microorganisms can colonize the membrane or tank interior. This is a use-and-maintenance issue, not a manufacturing defect, but critical to address.
Leachables from plastic tubing or fittings
The system includes plastic tubing and connection fittings; these are typically food-grade and FDA-approved, but no specific testing data for the GRO-350B is published. Leaching risk increases if water sits in the system for extended periods or if tubing degrades over time.
Membrane degradation and fragment release
RO membranes have a finite lifespan and can degrade under high pressure, chlorine exposure, or improper storage. Pentair does not publicly disclose whether degraded membrane material can release particles or residues; replacement on schedule is the primary control.
Housing corrosion or metal leaching
Stainless steel housing is resistant to corrosion under normal household water chemistry. No public record of lead, cadmium, or other heavy metals leaching from Pentair RO housings.
Microbial contamination from source water bypassing filters
If pre-filters are maintained, reverse osmosis membrane effectiveness for bacteria and viruses is well-established in literature. Failure mode is user-neglect, not design flaw.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% confidence. It is not a lab result.
No independent PFAS lab test is on record for this exact product. A lab test could move the score in either direction.
The brand has not made a specific, verifiable PFAS-free statement, so part of this score reflects that missing disclosure rather than a confirmed material.
Formulations and coatings change between production runs. Always check the current label before buying.
More under-sink ro systems grades
How we score: every product runs through the same public 0–100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.